Hydraulic cushion for metal presses



March 19,' 1929., F. J. RODE HYDRAULIC CUSHION FOR METAL PRESSES FiledApril 18. 1927 Patented Mar. 19,.: 1.929. UNITED STATES PATENT OFFICE.

FREDRICH J'. RODE, OF CHICAGO, ILLINOIS, QOMPANY, AOlla" CHICAGO,ILLINOIS,

ASSIGNOB. T MARQUETTE TOOL MFG. A CORPORATION OF ILLINOIS.

HYDRAULIC CUSHION 'FOR METAL' PRESSES.

Application filed April 18, 1927. Serial No.. 184,603.

This invention relates to improvements in` 10 die member,

hydraulic cushions particularly adapted v though not necessarily limitedin its use in sheet metal presses in which. the metal is shaped by meansof coopera-ting dies, one of which dies is reciprocable toward and awayfrom the other, the work being clamped or held by means 'of a blank orwork holding element that co-operates with a reciprocable the blank orWork holding element being resisted in its movement iny one direction bythe said cushion, and one of the objects of the invention is-to providean improved hydraulic cushion of this character in l5 which apredetermined quantity of liquid is used inthe cushion, the cushionembodying cylinder and piston members, the liquid being circulated fromone side to the other of the piston for establishing the resistancepressure and to the other side of the piston to permit the pressure tobe relieved.

A further object is to provide improved means for restoring the blank orwork holder to its normal position.

To the attainment of these ends and the acoomplishmentof other new anduseful objects as will appear, the invention consists in the features ofnovelty in substantially the construction, combination and arrangementof the several parts hereinafterinore fully described and claimed andshown in the accompanying drawing illustrating this invent-ion, andinwhich'- A Y Figure 1 isa view in side elevation, partly broken away,partly in section and with parts omitted of a sheet metal press havingan hydraulic cushion constructed in accordance with vthe principles ofthisinvention applied thereto.

Figure 2 i's an enlarged detail sectional view of the pressurecontrolling valve.

Figure 3 is a detail sectional View taken on line 3 3, Figure 2. l l

Referring more particularly to the drawing the numeral designatesgenerally the frame of a.. sheet metaly press having a reciprocable ram11 to which a die 12 is connected. rEhe ram is reciprocable by means ofa link 13 connected with a crank shaft 14, the latter being driven inany suitable manner (not shown) Mounted upon the bed plate 15 of the machine is a die 16 with which a work or blank holding member 17co-operates. The blank or work holding member 17 is supported byA meansof pins 18, which in turn pass loosely through the bed plate l5 and aresupported by means of a pressure pad oryplate 19.

All .of the above referred to parts are of the ordinary and well knownconstruction.

Supported beneath the lbed of the machine, preferably in a pit 20, is asupporting member 2l held in position by means of suitable hangers 22which are secured to a suitable fixed part of the machine.

3 Mounted upon the supporting member 2() is a cylinder 23 of any desiredsize and diameter and reciprocable in the cylinder is a piston 24,having a piston rod 25 which passes through a suitable packing 26 in theend of the cylinderand is secured in any suitable manner such as bymeans of fastening devices 27 to the bottom of the pin plate or pad 19.

rThe pad or plate 19 is supported by means of bars or rods 28constituting hangers. These bars 28 are secured to the bed plate 15in'any suitable manner, preferably by threading the ends of the rodsthereinto. rllhe rods depend from the plate and are provided withadjustable nuts or collars 29 on the free end thereof.

Resiliently yielding members, such as coil springs 30 encompass the rods28 with one end engaging the lower face of the pin plate or pad 19, andthe other ends of the respective springs engage washers 31 whichencompass the rods 28 and Vrest against the nuts 29.

rlhe cylinder is provided with a fill opening 32 above the piston 24,and liquid is supplied thereinto from a suitable source through a pipe33 in which a controlling valve 34 may be arranged. A check valve 35 isalso arranged in the pipe to prevent liquid from suitable guide 40. Oneend of a coil spring- 41 rests against a collar 42 secured to the valvestem 39. The other end of the spring engages a collar or abutment 43carried by a stem 44 which has threaded engagement with an vabutment 45Iand the stem 44'is provided with. an operating handle 46. By rotatingthe handle 46 the tension of the spring 41 may be varied and therebythepressure which 11o openings 47 which form communication between thevalve casing and the passage 36. A valve 48, preferably in the form ofan annular member, is provided to close the be closed by the ton uponthe liquid beneath the piston.

`the pin plate or pad 19 or pressure plate 19.

openings 47. This is accomplished by means y of rods 49 which areconnected with the valve 48 and pass loosely through the adjacent wallof the valve casing 37. Springs 50 encompassA the rods 49 and tendnormally to move the valve 48'in a direction to close the passages47.The valve casing 37 also has an openin 51 to which is'connected a pipe52 that alsoxas communication with an opening 53 preferably adjacent thetop of the cylinder, and on the' other side of the piston 24, so thatthe liquid may circulate from beneath the piston 24, through the pipe'52to the top side of the piston through the opening 53.

The valves 47 and' 48 are disposed between the` opening 51 in the casing37 and the opening 36, the valve 48 being unse'ated by the pressure ofthe liquid iiowing from the top of the piston so that the liquid willenter the bottom of the cylinder while the valve 48 will pressurecreated by the pis- The valve 38 is set for a predetermined pressure.and will be `unseated by pressure created upon the liquid under thepiston 24 by the action of the piston upon they liquid and when suchpressure eXcee s the pressure to which the valve 38 is set.

- The operation of the machine is as follows. In Figure 1 of the drawingthe parts are shown in their normal or initial position, that is withthe blank or work holding element 17 in position to co-operate with thedie 16 to support the work 54, and the lpiston 24 will be at'thel limitof its upwardl stroke'in the cylinder 23. I

The valve,38 is first set to the pressure which it is desired toestablish and the pressure pad or pin plate 19 will be supported by Ymeans. of the resiliently yielding elements 30.

When the ram 11 descends and the die 12 contacts with the work 54,. afurther lower'- ing movement of the ram will cause the work to -beshaped over the dies.. `At the same time will be depressed by means ofthe pins 18 against the liquid in the cylinder' beneath thepiston 24.The

lowering movement of the pad 19 will also cause the reslliently yieldingelements 30 tos be compressed so that energy will be stored therein. l

The springs 30 however serve only the purpose of returning or restoringthe pad or pressure plate 19 and the energy stored -inthe springswill-be negligible with respect to any resistance pressure createdthereby against' the lowering movement of the pad As the piston 24descends the lowering movement of the pin plate or pad 19 will beyieldingly resisted by the hydraulic pressure created upon the liquidbeneath the piston, )which pressure will continue until the pressureexceeds which holds the valve 38 upon its seat. When the pressure of thevalve 38 is exceeded the valve be unseated by the liquid and theliquidwill iow into the valve casing 37, thence out of the opening pipe52, intothe opening 53 to the top side of the piston 24.

When the ram 11 starts to ascend the pin plate or pad' 19 will be raisedby the energy stored in the resiliently yielding element 30 and thiswill raise the piston 24 in the cylinder 221- The liquid on the topside'of the piston will be discharged through the'opening 53, throughthe pipe 52 chamber 37 and from the valve chamber 37 into the openings49 against the valve 48 to lunseat the latter, which will permit theliquid to be vdischarged through the opening 36 back into the cylinderbeneath the 'piston 24.

The valve 35 will be closed by pressure so as to prevent the liquid frombeing delivered into the pipe 33 on the upstrokeof the piston 24.

lVith this improved construction it will be manifest that the hydraulicpressure may be controlled at any time during the -cycle of operation ofthe press by adjustment of the tension of the resiliently yieldingelement 41by adjusting the handle 46.

Furthermore by adjusting the tension of the resiliently yielding element41 the degree of pressure necessary to unseat the valve v38 may becontrolled at will.

It will alsobe manifest that with this improved construction zi?predetermined quanti- 51, through the into the valve ty of liquid-may beemployed and will be- I 'circulated from one'side to the other side ofthe piston durino the operation of the press.

While the prei? rred form of the invention has been herein shown anddescribed, itis to be understood that various changes maybe made in thevdetails of construction and in the combination and arrangement of thesevleral parts, within the scope of the claims, 'without departing fromthe spirit of this invention.

What is claimed as new is 1. A pressure cushion for sheet metal pressesembodying cylinder and piston members, hydraulic means for resisting therelative movement of said members in one direction, a single conduit forleading the liquid back and forth fromone'lside to the other side of thepiston, a conduit for movement of the liquid 1n one directiontherethrough, variably yielding means for holding said valve closed, andan additional valve for closing the @metten p resisting the relativemovement of said memoperating K site directions,

1,706,073 s Q f duit `or movement of .the liquid in the lastv -saiddirection therethrough and operating to permit the liquid to.A flowthrough said pas- Sage in the opposite direction.

2. A pressure 'cushion for sheet metal presses embodying cylinder andpiston members, hydraulic means forresisting' the relative movement ofsaid members in one directionj, a single conduit for leading. the liquidback and forth from one side to'the other side of the piston, oppositelyopening valves for controlling the iiovv of liquid through said singleconduit,and means for establishing a 'predetermined pressure upon one ofsaid valves and against which pressure the valve is adapted to beunseated by`the pressure-of the liquid thereupon.

3. A' pressure cushion for Sheet metal presses embodying cylinder andpiston members, hydraulic means for resisting the rela. tive movement ofsaid members in one direction, a single conduit for leading the liquidback and k'forth from one side to the other side of the piston,oppositely opening valves i for controlling the How of liquid throughsaid single conduit, means'for establishinga predetermined pressure uponone of said valves and against which pressure the valve is adapted to beunseated by the pressure of' the liquid thereupon, and means forvarying` at will the said the said valve. F v

LCA self-contained pressure cushion for sheet metal presses embodyingcylinder and piston members,.said cylinder containing'a predeterminedsupply of liquid, said liquid predetermined pressure upon bers in onedirection, a single'conduit for leading the liquid back and forth fromone side to the other side of the piston, opposit'ely g valves forcontrollindthe flow' of liquid through said-single conduit in .oppoandmeans` for establishing 5 and maintaining a predetermined resistancepressure upon one of. said valves and against which pressure thevalve'is adapted to be unseated by theoperation of the liquid there-l'against.

5. A self-contained' pressure cushionfor sheet metal presses embodyingcylinder and piston members, said cylinder containingja predeterminedsupply of liquid, said liquid A, resisting the relative movement of saidmem- 'bers in one direction,

leading the liquid back and f orthfrom one side to the other sidelof thepiston, oppositely operating valves for controlling the'iow of liquidthrough said single conduit in opposite directions, means forestablishing and maintaining a predetermined resistance pressure uponone of said valves ,and agalnst which pressure the valve is adapted to.be unf seated bythe operation of the liquid thereagainst, and means forvarying at will the Ysaid predetermined resistance pressure.

lbodying cylinder and piston members,

a single conduit for' 6. A pressure cushion for sheet metal pressesembodying a pressure pad, a cushion for resisting the movement of thepad in one direction, said cushion embodying cylinder and piston membersone of which is operatively connected with the said pad, a liquid in thecylinder, a conduit for leading the liquid from one side to the otherside of the piston, means for controlling the conduit and operable undera predetermined pressure created upon the liquid by the movement ofVsaid pad, and means separate from the cushioning means for supportingthe pad, the last said means operating to restore the pad.

7 A pressure cushion for sheet metal presses embodying a pressure pad,an hydraulic cushion for resisting the movement of the pad in onedirection, saiducushion einbodying cylinder and piston members, a by`pass for transferring the liquid in the cylin-y der from one side to\theother side of the piston, a valve for controlling the by pass, meanscreating a predetermined pressure upon said valve and against Whichpressure the valve is adapted to be opened by the pressure createdAyielding means being rendered active to'restqre the pad by the movement-of the pad in one direction. I v 8. A pressure cushion for sheet metalpresses embodyingV a pressure pad, an hydraulic cushion for resistingthe movement of the pad in one direction, vsaid cushion rellippass' fortransferring the liquid in the cylin der from one side to the other sideof the piston, a valve -for controlling the by pass, means creating apredetermined pressure upon said valve and against which pressure thevalve is adapted to be opened by the pressurecreated upon the liquidunder the movement of the pressure pad in one direction, means forvarying at will the pressure of the last said means upon the valve, andresiliently yielding means separate from the cushioning means forsupporting the said pad and serving to restore the pad, the saidresiliently yielding means being rendered active to restore the pad bythe movement of the pad in one direction. 9. A vpressure cushion v forsheet metal presses embodying a pressure pad, resiliently supporting theSaid means from a stationary part of the press, the first said meansoperating to restore the pad, an hydraulic cushion for-resistingthemovement of the pad in one rylelding means separate from the cushioning`means for: supporting said pad, means for controlled valve forcontrolling the said conduit and for causing a predetermined pressure tobe exertedupon the liquid before the conduit Will be opened, the saidpad being restored entirely by the energy created in -said resilientlyyieldingmeans When the pad is moved'against the said predeterminedpressure in the cushion; Y

10. A pressure cushion for Dsheet metal presses embodying a pressurepad, hanger members connected With a fixed part of the press,resiliently yielding members separate from the cushioning means andsupported by the hanger members and operating upon the pad to supportand to restore the same, an hydraulic cushion for resisting the movementof the pad in onedirection, said cushion embodying cylinder and pistonmembers relatively movable and one of which last said members isconnected with the pad, a conduit for transferring the liquid in thecylinder from one side to the other side of the piston, a valve for cotrolling" said conduit and adapted to be opened by the flow ofliquid inone direction through the conduit, and means 4 for creating apredetermined resistance pressure upon the valve against the actionofthe 'A vliquid.

11. A pressure cushion for sheet 'metal presses embodying a pressurepad, hanger members connected with a fixed part of the press,resiliently yielding members separate from the cushioning means andsupported by the hanger members and operating upon the pad to supportand to restore the same,.an

hydraulic cushion for resisting the movement of the pad in onedirection, said cushion embodying cylinder and piston members relativelymovable and one of which last said members is connected with the pad, aconduit for transferring the liquid in the cylinder .from one side tothe other side of the iston,

a valve for controlling said'conduit and 'from the cushioning means andsupported by the hanger members and operating upon the pad to supportand to restore the same, an hy:

draulic cushion for resisting the movement of the pad in one direction,said cushion embodying cylinder and piston members relatively movableand one of which last. said members 'dis connected with the pad, saidcylinder holding and maintaining a predetermined supply of liquidtherein, a conduit for transferring the. liquid in the cylinder from oneside to the other side of the piston, a valve for controlling saidconduit and adapted to be opened by the flow of liquid in one directionthrough the conduit, and means for creating a predetermined 'resistancepressure -upon the valve against the action of the liquid. l

13. The combination with a movable support for a blank .or Work holder,resiliently yielding means separate from the cushioning means forsupporting and restoring said support, an hydraulic cushion forresisting the movement of said support and draw ring in one direction,said cushion embodying cylinder and piston members relatively movableand one of which is connected with said support, variable resistancemeans for controlling the resistance exerted by the cushion element uponthe liquid, and means whereby the liquid may be conveyed from the'pressure side of the piston to the other side thereof,`the resistanceof the said resiliently yielding means to the movement of the workholder port, variable resistance means for control-Y ling the resistanceexerted by the cushion element uppn the liquid, and means whereby theliquid may be conveyed from the pressure side of the piston to the otherside thereof, Athe resistance of the. said resiliently yielding means tothe movement of the work holder and support in a direction to create aresistance pressure upon the liquid being negligible, the saidresiliently yielding means constituting the sole means for restoring thedraw ring and support therefor.

15. A pressure cushion for sheet metal resses embodying cylinder andpiston mem- .ers, hydraulic means for resisting the .relaf tive movementof said members in one direcyembodying a lmember having an openingtherethrough, a valve to close said opening from one side ofthe member,'there being additional openings through said member, a

valve for closing said additional ,openings from the opposite (sideo'said member, said valves Workin in oppositionto each other andvariable elding means for holding one of the said va ves closed.

16. A pressure .cushion for sheet -meta presses embodying cylinder andpiston members, hydraulic means for resistingthe relative movement ofsaidmembers in one direction, a conduit for leading the liquid back andforth from one side to the other side of the piston, a valve forcontrolling the movement of the liquid through the conduit, said valveembodying a member having an opening therethrough, a valve to close saidopening from one side of the member, there being additional openingsthrough said member, a

10 valve for closing said additional openings from the opposite vside ofsaid member,v said valves Working in opposition to each other, springsindividual to the valves for respectively seating them, and means forvarying at Will the stress of one of the springs upon its respectivevalve.

In testimony whereof I have signed my' FREDRICH J. RODE.

